Ps 100:1
100:1 <> Make a {a} joyful noise unto the
      LORD, all ye lands.

      (a) He prophecies that God's benefits in calling the
          Gentiles will be so great that they will have
          wonderful opportunity to praise his mercy and rejoice.

Ps 100:3
100:3 Know ye that the LORD he [is] God: [it is] he [that] hath
      {b} made us, and not we ourselves; [we are] his people,
      and the sheep of his pasture.

      (b) He chiefly means concerning spiritual regeneration, by
          which we are his sheep and people.

Ps 100:4
100:4 {c} Enter into his gates with thanksgiving, [and] into his
      courts with praise: be thankful unto him, [and] bless his

      (c) He shows that God will not be worshipped, but by those
          means which he has appointed.

Ps 100:5
100:5 For the LORD [is] good; his mercy [is] {d} everlasting;
      and his truth [endureth] to all generations.

      (d) He declares that we should never be weary in praising
          him, seeing his mercies toward us last forever.